Cytokinin has been implicated in many plant growth and developmental processes, and transcription factors are fundamental regulators of gene expression. A MYB and two AP2/ERF transcription factors whose transcript levels are up-regulated over several time points in response to the plant hormone cytokinin have been identified. The spatial and temporal regulation of these three transcription factors will be studied through the generation of transgenic plants harboring promoter reporter fusions, northern blot analysis and by real time PCR. In parallel, knockout mutants for each gene will be identified and characterized for alterations in developmental or hormonal responses in order to further reveal the function of these genes. I will identify potential targets, co-regulator and upstream activators of these transcription factors by examining genome wide expression profiles using Affymetrix gene chips of transgenic plants following the induction of transcription factor fusions to global activation and repressor domains. I will also search for proteins that interact with these transcription factors using yeast two-hybrid analyses and identify potential cis acting DNA targets of each transcription factor. In summary this proposal is designed to elucidate the role of three transcription factors in cytokinin regulation. [unreadable] [unreadable]